In a particular example, the invention relates to an illumination system comprising a plurality of lamps. Each lamp is provided with a network device capable of switching the corresponding lamp ON or OFF, and possibly capable of dimming the lamp. In the case of an armature with multi-colour lamps, the lamps can be ordered to make a certain desirable mix colour. A user-operated remote control is capable of issuing command signals to the network devices over a communication path that may be wired but preferably is wireless; a preferred way of communication is via RF signals. Thus, the user can remotely operate his illumination system without needing to operate individual switches located with the individual lamps. Further, the system does not require a new infrastructure: an existing lightbulb may simply be replaced by a new lightbulb having the associated network device.
In the following discussion, for sake of convenience, reference will be made to a “lamp” in cases where actually the network device of such lamp is intended, as should be clear to a person skilled in the art.
In order to be able to operate a plurality of lamps individually, it is necessary that the lamps can be distinguished from each other. Therefore, each lamp has a unique ID code or address code, and the command signal issued by the remote control contains an instruction part as well as a part indicating the addressee, i.e. the lamp for which the instruction is intended; the instruction part tells this lamp what it is expected to do.
The command signal may also contain a request for acknowledgement; in that case, apart from receiving and obeying the instruction, the network device also sends an acknowledgement message to the remote control, so that the remote control knows that its command signal has been received by the addressee network device. If such acknowledgement message is not received quickly enough, the remote control will automatically resend the command signal, without the user needing to actuate the corresponding command button again.
The system further comprises a memory containing network definition information. This memory will be indicated as network definition memory. The network definition information comprises, inter alia, a list of ID codes of network devices and a list of ID codes of corresponding remote control devices. It is noted that there may be more network devices in the neighbourhood taking part in the communication and therefore per definition being part of the communication network, but if a network device is not included in the network definition information (i.e. it is not on the list), it can not be addressed and therefore not operated by the remote control. Further, it is noted that there may be more remote control devices in the neighbourhood, but if a remote control is not included in the network definition information (i.e. it is not on the list), its command signals will not be accepted or obeyed.
Further, the network definition information may comprise a table defining which network device (ID code) is associated with which command button. It is possible that the remote control has command buttons associated with individual lamps. However, it is preferred that one command button is capable of operating a group of lamps simultaneously. In that case, the network definition information may comprise, for each command button, a list of network devices (ID codes) associated with that particular command button, or, alternatively, a list defining which network devices are member of which group as well as a table defining which group is associated with which command button.
The network is not static. It is possible that lamps are added or removed, or that the group assignment of a lamp is changed. Thus, there is functionality allowing the user to amend the network definition memory. The combination of network definition memory and the amendment functionality will be indicated as “coordinating means”. In a suitable embodiment, the coordinating means are implemented as a separate device, which will be indicated by the phrase “coordinator”. However, the coordination function may also be integrated with other network devices, for instance a remote control. An advantage of a separate coordinator device lies in the fact that the remote control is preferably implemented as a light-weight battery operated device while the coordinator is preferably provided with constant power from mains so that its settings are not lost when the batteries run empty.
A particularly suitable communication protocol for implementing the present invention is Zigbee. Since Zigbee is known per se, as it is an open source standard, a detailed description of Zigbee is omitted here.